[llvm] [Passes] Run SimpleLoopUnswitch after introducing invariant branches. (PR #81271)

[Alina Sbirlea via llvm-commits]

https://github.com/alinas commented:

This brings back the discussion that we really should have better infrastructure in the NPM to specify the conditional running of passes. The `extra-vectorizer-passes` change was supposed to be a one time approach.

Do you have a measure of how this affects execution time for some workloads (e.g. spec)? Could you also test this on https://github.com/google/fleetbench?

https://github.com/llvm/llvm-project/pull/81271